For several generations now it has been known to utilize concrete blocks of a standard size in the construction of homes, apartment houses, office buildings and many other structures. Although block size can vary in accordance with the particular utilization to be made, one standard size of concrete block measures 8".times.8".times.16", and has two rather large cavities separated by the center web of the block.
For reasons of strength, it is well known to place the concrete blocks in a "staggered" relationship when constructing a wall, with one layer or tier of blocks offset approximately 8" from the tier directly below it. The configuration of these standard size concrete blocks is such that the cavities of the numerous blocks utilized in the construction of a wall are to a substantial extent caused to line up vertically.
Many building codes pertaining to both residential and commercial buildings require a special construction technique to be utilized at the location where one wall portion intersects another wall portion, such as in a 90.degree. relationship. As one example, reinforcement bars ("rebars") are frequently inserted down along the block cavities defined at the corners where one wall intersects the other. In addition to this, concrete is usually poured down through the intersecting cavities of the blocks located at such corner.
Another important constructional technique required by most building codes is the pouring of a lintel along the top of the substantially completed block wall. In this instance, "channel" type concrete blocks are utilized as the top member of each wall portion, with rebars placed horizontally in the aligned channels extending along each wall portion. Bent rebars are utilized at each corner. As a result of this construction, concrete can be poured into the channel-type concrete blocks utilized along the top of each wall, with the bent rebars utilized at each corner preventing the corners from separating. This type of construction is much stronger than would have been the case if the concrete blocks had not been topped off with poured concrete, and the intersecting corners had not been suitably reinforced.
Various efforts have been made in the past to avoid the cost and labor expense involved in the creation of walls constructed of concrete blocks, and one of these prior art techniques is set forth in the Gregori U.S. Pat. No. 3,552,076 entitled "Concrete Form." The Gregori patent teaches the utilization of a self-supporting concrete form of foamed polymeric material molded in one piece and involving two spaced longitudinal walls. One or more partitions may be utilized along the length of Gregori's concrete form in order to form vertically disposed apertures for receiving molten concrete. Although this patentee teaches the utilization of means providing reinforcement for the concrete poured into these vertically disposed apertures, it is to be seen that Gregori's molds are not much taller than the height of conventional concrete blocks, which of course means that considerable speed in the creation of a wall utilizing Gregori's technique would not be readily possible. In addition, Gregori's patent exhibits no comprehension of the use of a trough-like recess extending along the upper section of his molds for receiving molten (wet) concrete, nor any recognition of a technique wherein the builder is able to economize in the use of concrete by selecting only certain vertically disposed apertures of his molds to receive the molten concrete.
A generally similar teaching is involved in Gregori's U.S. Pat. No. 3,788,020 entitled "Foamed Plastic Concrete Form with Fire Resistant Tension Member," but this teaching involves the utilization of metal members bridging between the elongate side members of this particular concrete form, thus increasing labor costs as well as material costs insofar as the creation of these concrete forms is concerned.
The Nicosia U.S. Pat. No. 3,872,636 entitled "Light Weight Load Bearing Metal Structural Panel" and the DeLozier U.S. Pat. No. 4,223,501 entitled "Concrete Form" each necessitate the use of concrete forms of lightweight material needing metal members for strengthening purposes. The Nicosia patent involves the use of sections of expanded metal, whereas the DeLozier patent involves transverse connecting members serving to support and position the sidewall members as well as to define mold cavities, but these techniques necessarily increase the cost of material and labor.
The Ott et al U.S. Pat. No. 4,604,843 entitled "Lost-Form Concrete Falsework" teaches the use of insulating slabs of foam material that are held in an upright orientation in a spaced apart relationship so that concrete can be poured therebetween. In a similar manner to certain of the other prior art techniques, these patentees teach the use of elements of a ladder-like configuration that are utilized for holding the slabs of foam material in the properly spaced relationship. Obviously a wall of this construction is quite heavy, and like the other patents of this type, the amount of concrete utilized in the construction of the wall cannot be varied in accordance with the needed strength of the wall.
The Berrenberg U.S. Pat. No. 4,879,855 entitled "Attachment and Reinforcement Member for Molded Construction Forms" pertains to an arrangement in which the left and right halves of a form for receiving wet concrete are held together by expanded metal mesh. This arrangement is expensive and the patentee says nothing regarding an option on the part of the builder for utilizing a substantial amount of concrete in the event a wall of great strength is needed, or a less amount of concrete in the event strength demands are not high and it is desirable to save on the expense of concrete.
A somewhat similar technique is set forth in the Boeshart U.S. Pat. No. 4,889,310 entitled "Concrete Forming System" in which opposed polystyrene panels are stacked to form a pair of parallel, spaced apart walls held apart by special tie members, with concrete to be poured between the members. Like Ott et al, the Boeshart technique brings about the creation of a very heavy wall, rather than a lightweight loadbearing wall in which the amount of concrete utilized in the wall can be selectively modified.
Weir U.S. Pat. No. 5,247,773 entitled "Building Structures" teaches the use of extruded plastic utilized in the creation of building components, with these plastic members being equipped with elongated male and female means whereby such components can be secured together to create walls and the like. While this technique may be usable for internal walls, this technique does not enable walls of considerable weight bearing capability to be created.
Nicolaidis et al U.S. Pat. No. 5,329,741 entitled "Portable Constructional Element and a Process for its Production" teaches the creation of a portable constructional element made up of a foamed cementitious material provided with an outer plastic covering. While this technique may be usable in wall construction of a certain type, this procedure would not be suitable for utilization in the creation of exterior loadbearing walls.
Collins U.S. Pat. No. 5,404,685 entitled "Polystyrene Foamed Plastic Wall Apparatus and Method of Construction" teaches the use of foamed plastic panels able to be inserted in the grooves of columns, but as is obvious, these panels have very little strength and would not be suitable for bearing any considerable mount of weight.
The Record U.S. Pat. No. 5,440,846 entitled "Construction for Building Panels and Other Building Components" teaches a composite building component of a cement composition utilizing an amount of diatomaceous earth or other thermally insulating material in a specified ratio to entrained air, thus to provide a degree of thermal insulation. This technique, however, bears little relationship to the rapid construction of loadbearing walls wherein the amount of concrete utilized in the wall can be varied in accordance with the need for strength.
It was in an effort to overcome the shortcomings of these patents and the need for rapid loadbearing wall construction that the present invention was evolved.